///2009 Abstract Details
2009 Abstract Details2018-05-01T17:45:11+00:00

Does high-dose oxytocin elevate maternal body temperature in the mid-trimester?

Abstract Number: 50
Abstract Type: Original Research

Alicia C C Vogt M.D.1 ; Alice Esame Student2; Barry D Shaw M.D.3; John Owen M.D.4; Michael A Froelich M.D., M.S.5

Background:

Some investigators noted an increase in temperature during labor (1) that has been associated with epidural anesthesia (2) but is more likely an abnormal response confined to a subset of patients (3). Another possible explanation for the temperature associated with labor may be related the endocrinology of parturition. oxytocin, released endogenously by the hypothalamus or used clinically to induce uterine contractions and labor, stimulates the release of prostaglandin E2 and F2-α by activation of phospholipase C. Circulating prostaglandin E2 is the ultimate mediator of a febrile response. Recognizing this mechanism, we test the hypothesis that oxytocin when used in high doses to induce uterine contractions may have a direct pyrogenic effect.

Methods:

We reviewed 279 charts of patients admitted from January 2005 to June 2008 for mid-trimester fetal demise (gestational age 14 to 21 weeks). After excluded patients who received prostaglandins, NSAIDs or Tylenol, who were suspected to have chorionamnionitis, febrile on admission (temperature greater than 38 ℃) or had incomplete data, we found 23 charts of patient who had been treated with high-dose oxytocin and 20 charts of patient who delivered spontaneously. We calculated that we needed at least 16 cases per group to achieve 80% power to detect a 0.5 ℃ temperature change from admission to delivery (α = 0.05, SD = 0.5 ℃). We compared the change in temperature -admission versus delivery of the placenta - using a paired t-test assuming unequal variances. Within the oxytocin group, we tested whether there was an association of oxytocin dose and change in temperature using univariate regression.

Results:

The average total oxytocin dose was 370 Units (Range: 50 to 3150 Units). In contrast to our hypothesis the average change in temperature was lower in the oxytocin group (- 0.21 0.48 ℃) than in the control (0.14 0.6 ℃) group (t=-1.96, df=35, p=0.057) and there was no association of oxytocin dose and change in temperature (F=0.50, df=41,1 p=0.48).

Conclusion:

The observed data do not support our hypothesis that oxytocin has a pyrogenic effect when used to induce labor in midterm pregnancy. Since we studied mid-trimester pregnancies, we cannot exclude the possibility that oxytocin may have an indirect effect on temperature through its labor-augmenting effect in term pregnancy.

Literature:

1.) Camann WR, Hortvet LA, Hughes N et al. Maternal temperature regulation during extradural analgesia for labour. Br J Anaesth 1991;67:565-8.

2.) Gonen R, Korobochka R, Degani S, Gaitini L. Association between epidural analgesia and intrapartum fever. Am J Perinatol 2000;17:127-30.

3.) Goetzl L, Rivers J, Zighelboim I et al. Intrapartum epidural analgesia and maternal temperature regulation. Obstet Gynecol 2007;109:687-90

SOAP 2009